{
    "types": [
        {
            "id": ["exact", "X"],
            "kind": "record",
            "fields": [
                {"name": "x", "value": {"kind": "string"}, "required": true},
                {"name": "y", "value": {"kind": "boolean"}, "required": true}
            ]
        },
        {
            "id": ["exact", "Y"],
            "kind": "reference",
            "to": ["exact", "X"]
        },
        {
            "id": ["exact", "Z"],
            "kind": "record",
            "fields": [
                {"name": "z", "value": {"kind": "string"}, "required": true}
            ]
        }
    ]
}